Compounds of lasofoxifene, nafoxidine and the like are known as selective estrogen receptor modulators (SERM's). “Selective estrogen receptor modulator” is a generic term for pharmaceuticals which show an estrogen action, or which show an anti-estrogen action, depending on the organ or tissue. For example, such a pharmaceutical may show an anti-estrogen action with respect to the uterus, mammary glands or the like, while on the other hand showing an estrogen action with respect to postmenopausal osteoporosis, serum cholesterol, the cardiovascular system and the like. As such pharmaceuticals, in addition to lasofoxifene and nafoxidine, others such as tamoxifen and raloxifene are also known.
Among these, lasofoxifene shows promise as an agent for the prevention and treatment of postmenopausal osteoporosis, and currently large scale clinical trials are underway. The chemical structure of lasofoxifene, cis-6-phenyl-5-[4-(2-pyrrolidine-1-yl-ethoxyphenyl]-5,6,7,8-tetrahydronaphthalen-2-ol, is shown by the following Formula (30).

However, lasofoxifene has a tetrahydronaphthalene skeleton, and has geometric isomers, but because only the cis form has effects, an isolation step is necessary.
Further, the chemical structure of nafoxidine is shown by the following Formula (31).

Nafoxidine has a 1,2-dihydronaphthalene skeleton, and because there are two substituent groups bonded to two double bonded carbons, it has no geometrical isomers, but one of the two hydroxyl groups is substituted by methyl group, and the other is substituted by a 1-pyrrolidinylethyl group, and because a positional isomerism arises, the production efficiency becomes low.